Is also my experience now. 100ms works sometime - 150ms it works.
For safety reason I’ll choose 200 ms.
Quite enough as I need not change a snapshot during a song via bluetooth.
I will experiment with CC commands later when there is proper documentation, but I assume that the standard commands like CC-7 (Volume) and similar are the same as for other units.
Actually what i expect to take the longest time is the pedalboard switching, since it invoves reloading all the plugins and connections.
Merely switching a snapshot should be considerably faster, since you’re just updating parameters inside an already active pedalboard.
For the moment, I can now live with the system.
I don’t need bank changes at the moment because I have already built up my bread and butter pedal.
I might make a second one for more rocky stuff. (for another playlist)
I’m sure I’ll discover more secrets in the course of time - but there’s no hurry now.
Just testing my newly arrived WIDI Jack with the Mod duo.
WIDI Jack plugged into Duo MIDI in/out ports. It gets power from the Duo itself so no ext power required.
WIDI uHost plugged into Linux PC USB port. Gets power from USB, so also no ext power needed.
The two devices, once paired using the Android app, connect automagically at every power on. Perfect.
I fired up TouchOSC on the PC just to have a MIDI controller, told it to use the uHost MIDI ports and from then piloting the Duo plugins was just a matter of assigning knobs to controllers.
Easy and works well.
Well, changing a snapshot now works as described above.
I cannot say the same for changing a pedalboard.
First of all, there is no possibility to select a bank in which the pedalboards are collected.
I cannot address a desired pedalboard either.
Yesterday it was probably a random effect that only works with a certain setting, which I can’t reproduce now.
Sending the Channel No and the Prg-change command is obviously not enough.
I’ll have to be satisfied with the snapshot call for the time being, even though it annoys me that I can’t achieve a complete sound change of the DWARF via the setting list.
Yes, from what I know, banks can not be changed by midi messages, so you have to be sure you select the appropriate bank if you want to use MIDI to switch pedalboards.
Then, you need to make sure that the order of the pedalboards in the bank match the PC number you send with the controller.
Snapshots should be pretty much instantly changing. Pedalboards, as @Tarrasque73 said, take longer since all the plugins need to be loaded. So, mostly, the heavier the pedalboard is, the longer it takes to load.
For this, you need to select it going to the Banks view (push the footswitches B and C simultaneously) and you need there to get in the desired bank. The Program Change messages will then move according to the order of pedalboards that you have in that bank.
Actually, I just reied to check this on my Duo, as I detailed above.
In facts it REALLY seems that there’s something strange with pedalboards and MIDI.
I’m able to change snapshots with PC on the according channel, but messages sent to the pedalboard switching channel seem to be discarded, even though they are received (checked with MIDI display).
EDIT: I realized that in order for MIDI pedalboard switching you must disconnect the web interface.
This is intended,I think, even if extremely annoying, and I hope it can be changed in the future.
The worse thing I found out is that it seems that if I change pedalboards too fast, the device goes crazy and it loads pedalboards from another bank altogether!
This I think it’s a bug.
EDIT 2: what seems to happen is that the Duo just “loses” the loaded bank and reverts back to “All pedalboards”.
what may be happening is that the device/software from where you send the messages sends in a 0 to 15 format and MOD interpretes it on a 1 to 16. Isn’t this your case?
Nope, the fact, which is not much evident, is that you have to disconnect the device from the Web UI for MIDI pedalboard switching to work. I’d suggest at least a little text or something in the Web UI header to remind this, if possible.
The real issue is that if you try to change pedalboard too fast via midi it seems to lose the loaded bank and goes out to “all pedalboards”.
It’s true! I always forget this one. We are discussing some improvements on that. The idea is to have a notification popping up on that case.
We found this issue recently and are already trying to fix it.
Thank you for the answer. So it is true that I cannot select Banks via MIDI.
However, calling up a DWARF pedalboard of the bank that was previously selected does not seem to work.
I have not been able to send a PC command to the set channel for pedal board changes.
Snapshot changes are no problem - even with an upright USB connection to the GUI.
You should not have the WebGUI open
Why I should not have the WebGUI open when it works?.
Well, even a little thing like a popup, a warning label or a different background color would be of great help, if even someone “in the works” like you forgets about this from time to time! 
Glad to read you’re already on it. Thank you very much.
Because when the device is connected to the Web UI some functions are deactivated, including pedalboard switching via MIDI.
At the moment I only use snapshot change via MIDI.
This works with the Web UI connected.
I have currently postponed changing a pedalboard.
Adding on what @Tarrasque73 said, the WebGUI takes over one functionality that doesn’t allow to keep that. It’s not so simple to get a workaround that allows both, that’s why it is currently not possible.
The pedalboard switching should be as simple as the snapshot. It’s only required to not do it with the WebGUI open.
Thanks., I’ve understand.
Just for talking,that’s how I’m trying to arrange my pedalboards.
Banks are not easily switchable. You have to go deep in the device menu to swap to another when not using the GUI. So the best option is to use them to organize pedalboards with the GUI and optimally go to stage using just one bank that contains all pedalboards you expect to use in the set and some more.
Pedalboards are long to load. You can’t expect to switch them without interrupting the sound, so they are best used intended to be switched between songs, except if you have a long silent part.
To change instantaneously sound in the middle of a song, you have 2 roads. Using the footswitches (or a midi controller) to turn on/off an effect (or using a switch plugin bypass a series of effects) or using snapshots, which easily allow the simultaneous change of multiple parameters.
So, my “best practice” would be to have one pedalboard per song (or per group, if the majority of the group’s songs are quite similar, say AC/DC) and use snapshots/footswitches to manage the different moments of the song (intro, verse, solo, whatever)